I can even get an offset giraffe‐rider (or even zemel‐rider — presumably longer ones work too, if they'd fit on the board), even though normal giraffe‐riders (FXFX?) are apparently unsupported!
The way it works now is that an even number of y force the next leg to be orthogonal/diagonal with a stride of half that number + 1, while the next odd number of y then adds a sideway step of 1 to that. (So there is currently no way to specify a Zebrarider in the 2nd leg.) But the preprocessor would not recognize any rider beyond CC, and never generates more than the 5 y needed to request that. Duplication of extended atoms is indeed not supported. Initially I thought of atom duplication as a legacy feature, and preferred a range 0 for specifying unlimited-range riders. FX0 should work.
But the y extension still fails for e.g. [W?sfZZ] (also shouldn't that be fsNN ⁊c?), let alone pathological things like [C?fsZZ], so if we're making an effort to support direction‐type changes it probably deserves to be more general.
That I used sf in [W-sfNN] was nonsense (and in fact turned out to be buggy when I first tried it), as sfN means the same as fN: both forward-most moves. I had suppressed the multiple-y extension on oblique first leg, but there really is no need to do that, so I lifted that ban now, and [C-fNN] should work too.
Also speaking of the Z, [Z?sfB] currently gives me Zebra‐then‐Rook, and vice‐versa
This is a consequence of sf being an invalid direction specification for B after an oblique. The continuation here always uses the K system of directional specs, and I laid out the transparent path of Z before B so that it ends in the diagonal direction, which means that B is the f direction. The specification fs causes the underlying XBetza interpreter to apply atom rotation, making the continuation Rook-like. So this is an example where the directional spec overrules the atom type. (Which of course is the basis of XBetza, which doesn't even specify the continuation atoms.) [Z?fB] should have given you what you wanted.
Now that we can use incommensurate atoms, the definition of 'forward' continuation had to be extended. I did that such that after oblique this is the diagonal slide that stays in the same quadrant. While oblique after queen-like uses the degenerate 8-fold system, so that f refers to a pair of moves.
The way it works now is that an even number of y force the next leg to be orthogonal/diagonal with a stride of half that number + 1, while the next odd number of y then adds a sideway step of 1 to that. (So there is currently no way to specify a Zebrarider in the 2nd leg.) But the preprocessor would not recognize any rider beyond CC, and never generates more than the 5 y needed to request that. Duplication of extended atoms is indeed not supported. Initially I thought of atom duplication as a legacy feature, and preferred a range 0 for specifying unlimited-range riders. FX0 should work.
That I used sf in [W-sfNN] was nonsense (and in fact turned out to be buggy when I first tried it), as sfN means the same as fN: both forward-most moves. I had suppressed the multiple-y extension on oblique first leg, but there really is no need to do that, so I lifted that ban now, and [C-fNN] should work too.
This is a consequence of sf being an invalid direction specification for B after an oblique. The continuation here always uses the K system of directional specs, and I laid out the transparent path of Z before B so that it ends in the diagonal direction, which means that B is the f direction. The specification fs causes the underlying XBetza interpreter to apply atom rotation, making the continuation Rook-like. So this is an example where the directional spec overrules the atom type. (Which of course is the basis of XBetza, which doesn't even specify the continuation atoms.) [Z?fB] should have given you what you wanted.
Now that we can use incommensurate atoms, the definition of 'forward' continuation had to be extended. I did that such that after oblique this is the diagonal slide that stays in the same quadrant. While oblique after queen-like uses the degenerate 8-fold system, so that f refers to a pair of moves.